NEMATODE PARASITES OF BIRDS 



379 



Hosts. — Primary: Cygnus olor; secondary: Probably fish, ac- 

 cording to Jaegerskiold. 



Location. — In vesicles between the external coats of the proven- 

 triculus. 



Morphology. — Hystrichis (p. 375) : Body irregularly swollen in the 

 middle and posterior portions. The head end (fig. 440) also has a 

 marked bulbous swelling which is wider than long and provided 

 with 20 rows of large spines, directed posteriorly and thickened at 

 the base. In addition the anterior portion of the body is armed with 

 small spines which gradually disappear posteriorly. The circular 

 mouth is protractile and surrounded by a crown of small spines. 



Male unknown. 



£'','.' "'•'.'.',v3 :■■$ 



a 



Fig. 439. — Hystrichis COBONATUs. a, Head end; b, female, natural size; 



C, FEMALES TAIL. AFTER MoLIN, 1SG0 



Female 30 mm. long. Anus terminal, large; vulva at posterior 

 end of body, near anus. 



Life history. — Unknown; possibly similar to that of H. tricolor 

 (p. 376). 



Distribution. — Europe (Italy) . 



HYSTRICHIS KEGL&CTUS Jaegerskiold. 1909 



Synonyms. — Eustrongylus papillosum (Rudolphi, 1802) Diesing, 

 1851, part; Hystrichis papillosus (Rudolphi, 1802) Molin, 1861a, 

 part. 



In addition to the above, Jagerskiold lists Hystrichis, species Wedl 

 as a possible synonym and states that it is very close and possibly 

 identical with his new species. HystricMs, species Wedl, however, 

 was named //. wedlii by Linstow, emended by Jaegerskiold to //. 

 wedli and if the two species, H. neglectus and //., species Wedl are 

 identical, Jaegerskiold's species will fall as a synonym of //. wedli. 

 The fact that the larva described by Linstow at the same time that 



